Method and apparatus for forming clad metal products

ABSTRACT

The present invention concerns methods and apparatus for forming a clad product, such as a clad pipe or tube. Particular embodiments include a method for metallurgically bonding cladding material onto a metal substrate, the method including a step of providing a metal substrate comprising a pipe or a tube having a cladding composition arranged along an interior surface of the substrate to form a coated substrate, the interior surface arranged within an interior cavity of the substrate. A further step includes inserting a heat source into an interior cavity of the substrate, the heat source comprising an infrared, microwave, or radio frequency heat source, the heat source being mounted on a heat source-retaining housing, the housing comprising a cantilevered structure. An additional step includes applying heat discharged from the heat source to the coated substrate along the coated interior surface until the cladding composition metallurgically bonds to the substrate.

This application claims priority to, and the benefit of, U.S.Provisional Patent Application No. 61/451,114 filed Mar. 10, 2011 withthe U.S. Patent Office, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention generally relates the formation of metal cladding upon atarget substrate, and particularly to methods and apparatus for forminga cladding using a high energy density fusion cladding process and othervariations thereof.

Description of the Related Art

There exists an urgent need in the industry for corrosion, erosion andwear resistant clad products, and in particular clad pipes, plates andbars. These products have a wide variety of application in multipleindustries including oil and gas, chemical and petrochemical,infrastructure, marine, mining and mineral processing, for example. Ithas been reported that tens to hundreds of billions of dollars are spentannually to remedy the effects of corrosion in each such industry.Further, the surfaces of these products may also subjected to erosionand wear. For example, such products may be exposed to certainenvironments or employed to convey particular materials that may promoteerosion or wear along an exterior or interior surface of the product.

Several methods and processes have been used to manufacture clad metal,such as co-extrusion, roll bonding, explosion bonding, and weldoverlay/laser cladding. These processes, however, are labor intensive,costly, and/or may provide difficulties in obtaining desired cladding onparticular products. Accordingly, it is desirable to provide alternativesolutions for improved formation of cladding upon desired substrates.

SUMMARY OF THE INVENTION

The present invention generally concerns methods and apparatus forbonding cladding material onto a metal substrate, such as mechanicallyor metallurgically to a pipe or the like. Particular embodiments of thepresent invention include a method for metallurgically bonding claddingmaterial onto a metal substrate. Embodiments of such methods include thestep of providing a metal substrate comprising a pipe or a tube having acladding composition arranged along an interior surface of the substrateto form a coated substrate, the interior surface arranged within aninterior cavity of the substrate. Such embodiments further include thestep of inserting a heat source into an interior cavity of thesubstrate, the heat source comprising an infrared, microwave, or radiofrequency heat source, the heat source being mounted on a heatsource-retaining housing, the housing comprising a cantileveredstructure. Further steps of such methods include applying heatdischarged from the heat source to the coated pipe along the coatedinterior surface until the cladding composition metallurgically bonds tothe interior surface of the pipe.

Particular embodiments of the present invention include an apparatus formetallurgically bonding cladding material onto a metal substrate.Embodiments of such apparatus include a heat source housing, the housingcomprising a cantilevered structure, the cantilevered structureincluding a heat source arranged along a length of the cantileveredstructure and comprising an infrared, microwave, or radio frequency heatsource. Such embodiments of such apparatus also include a translationdevice adapted to receive a metal substrate comprising a pipe or a tube,the translation device being translatable relative to the heat sourceand configured to rotate the substrate relative the heat source.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more detailed descriptionsof particular embodiments of the invention, as illustrated in theaccompanying drawing wherein like reference numbers represent like partsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a cladding apparatus or system generallycomprising a substrate carriage and a heat source carriage for claddingthe interior surface of a substrate, where the substrate carriage istranslatable according to an embodiment of the invention.

FIG. 2 is an end view of the substrate carriage of FIG. 1, in accordancewith an embodiment of the invention.

FIG. 3 is a perspective exploded view of a gas discharging ring of theheat source carriage of FIG. 1, according to an embodiment of theinvention.

FIG. 4 is a front end view of the ring of FIG. 3 shown assembled andattached to a second plate of the heat source carriage of FIG. 1,according to an embodiment of the invention.

FIG. 5 is a section view of the gas discharging ring taken along line5-5 in FIG. 4, according to an embodiment of the invention.

FIG. 6 is a perspective exploded view of the gas discharge ring of FIGS.3-5 shown in association with a secondary gas discharge member inaccordance with a further embodiment of the invention.

FIG. 7 is an assembled view of the gas discharge ring and the secondarygas discharge member shown in FIG. 6.

FIG. 8 is an side view of the assembly shown in FIG. 7.

FIG. 9 is a rear end view of the secondary gas discharge member with thecover removed to show a fluid passage extending from fluid inlets tofluid outlets in accordance with a particular embodiment of theinvention.

FIG. 10 is a perspective view of a heat lamp and gas shielding devicefrom the heat source carriage in FIG. 1, according to an embodiment ofthe invention.

FIG. 11 is a perspective view of the gas shielding device of FIG. 10,according to an embodiment of the invention.

FIG. 12 is a perspective view of the gas shielding device of FIG. 11taken along line 12-12, according to an embodiment of the invention.

FIG. 13 is a bottom view of a first portion of the gas shielding deviceof FIG. 11, according to an embodiment of the invention.

FIG. 14 is a perspective view of a second portion of the gas shieldingdevice of FIG. 11, according to an embodiment of the invention.

FIG. 15 is a partial cross sectional view of pipe 80 with a claddingcomposition arranged along an interior bottom surface of said pipe, theheat source being arranged a distance D from said interior bottomsurface, according to an embodiment of the invention.

FIG. 16 is a perspective view of a pipe alignment means comprising aplurality of extensions having bearing means arranged at a free,terminal end of each such extension, the extensions extending from acentral member operably attached to the first plate of the cantileveredstructure, according to an embodiment of the invention.

FIG. 17 is an end view of the alignment means of FIG. 16.

FIG. 18 is a perspective view of the alignment means of FIG. 16, showingthe insides of each deformable extension and a deformation member withineach such member, according to an embodiment of the invention.

FIG. 19 is a perspective sectional view of the alignment means of FIG.18, showing the cross section of each extension, where the extensionscomprise a pair of deformable extensions and a rigid extension,according to an embodiment of the invention.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

Particular embodiments of the present invention provide methods andapparatus for cladding substrates, such as pipes, plates, and bars, forexample. Cladding comprises bonding a cladding or coating to a substrateor base material to form a clad product. Bonding may be achieved, forexample, by mechanical and/or metallurgical bonding. Cladding can bevaluable when applying cladding to a lower cost substrate to attain thedesired properties of any more expensive corrosion resistant alloys,which may offer more optimum corrosion, wear, and erosion resistance.For example, when the substrate is carbon steel, the final product notonly exhibits the desired properties associated with the cladding, butalso the superior strength, ductility, and weldability characteristicsassociated with the carbon steel substrate.

The present invention concerns methods and apparatus for forming a cladproduct. Particular embodiments of such methods may include providing ametal substrate comprising a pipe or a tube having a claddingcomposition arranged along an interior surface of the substrate to forma coated substrate, the interior surface arranged within an interiorcavity of the substrate. Cladding may be formed on any desiredsubstrate. In the embodiment shown in the figures, the substrate is asteel pipe. However, the substrate may comprise any desired form, suchas pipe, tube, bar, or plate, for example, comprising any desiredmaterial. In particular, the methods and apparatus discussed herein areparticular useful to clad the interior surface of any enclosedsubstrate, that is a substrate where the transverse width and height isenclosed, such as with a pipe or tube, where the pipe or tube has anouter circumference or perimeter enclosing the interior cavity. Asubstrate may also be used where the substrate is partially enclosed,where a portion of the substrate extends transversely in multiple planesso to define an interior surface, such as with a channel, beam, or anyparticularly shaped extrusion. By example, the substrate may be formedof a titanium alloy, high strength steel, a high strength low alloysteel, a thermo mechanically processed (work-hardened) heat treatedalloy, or an aluminum alloy. Prior to depositing any claddingcomposition onto the substrate, the substrate surface is prepared toreceive the composition using conventional cleaning or surfacepreparation methods, such as surface blasting.

Upon completion of any surface preparation, the cladding material isdeposited on the substrate surface. This may occur prior to processingor during processing. Cladding composition may comprise any desiredcomposition. For example, a cladding composition may form a corrosionresistant alloy, a metal, a fusion bonded epoxy, a ceramic metalcomposite, a paint, an organic or inorganic protective coating material,a nanocomposite, or an organic or inorganic polymer. Further, a claddingcomposition may comprise a thermosetting polymer, a thermosettingpolymer composite, a thermoplastic polymer, or a thermoplastic polymercomposite. By more specific example, cladding composition may comprise apowdered metal and/or organic or ceramer composite, such as a nickelbased alloy (such as alloy 625, alloy 825, and alloy 400), stainlesssteel, metallic glass, aluminum-zinc, or polymer/fusion bond epoxy tosteel surfaces. In particular embodiments, the cladding compositioncomprises a composition disclosed in: (1) International Application No.PCT/US10/35876 filed on May 21, 2010 and published Nov. 25, 2010 as WO2010/135721; and, (2) U.S. patent application Ser. No. 12/785,397 filedMay 21, 2010 and published Nov. 25, 2010 as US 2010-0297432, each ofwhich claim priority to U.S. Provisional Application No. 61/180,530filed May 22, 2009, all of which are herein incorporated by reference.Cladding composition is also referred to herein as cladding coating,cladding material, and precursor.

Cladding material may be deposited or applied to the substrate using oneor more application techniques based according to the specificapplication. Cladding material may also be deposited in any desiredform, such as a powder, slurry, paste, or preformed foil or sheet. Inparticular embodiments, the preformed foil or sheet may comprise anydesired shape, such as a planar sheet, a tube, or the like. Exemplaryapplication methods include electrostatic application, compressed airspray application, inert gas spray application, thermal spray, rolling(compressive bonding), centrifugal casting, fluidized powder,compression and gravity in slurry form, solvent liquefied powder, wipingpig, brushing, tape application, foil application, and mechanicalexpansion via a sleeve.

Particular embodiments of such methods include applying heat dischargedfrom the heat source to the coated substrate along the coated interiorsurface until the cladding composition metallurgically bonds to theinterior surface of the substrate. In particular embodiments, bonding ofthe cladding material to the substrate is achieved by application ofheat from a heat source that heats an area substantially larger than thearea by which welders and lasers produce. The heat source may compriseany known heat source, such as a heat lamp. In particular embodiments,the heat source is a high-density infrared (HDIR) plasma arc lamp. TheHDIR lamp is capable of providing pulsed or constant energy and largepower densities, up to 2,000 W/cm² or up to 20,000 W/cm² or more. In aparticular embodiment, arced lamp power densities are betweenapproximately 350 and 5700 W/cm², although any power density may beemployed as desired for a particular application. A means of protectingthe heat source may also be employed to protect the heat source fromdamage that may result during a bonding operation, where the heat sourcemay be subjected to reflective heat, heat by convection or conduction,splatter of material, and/or exposure to undesired gases or fluid. Forexample, a means for shielding the heat source may be employed thatdirects a flow of air or gas across the heat source to create a flowinggas barrier between the heat source and the bonding area, which attemptsto isolate the heat source from any undesired fluid or material withinthe bonding area. This gas flow may flow at any rate and have anythickness as desired or as necessary to protect the heat source for anyparticular application. For example, the thickness may be increased whenheat exposure increases and/or the amount of splatter, debris, orcontaminants being directed towards the heat source increases.

While the heat source may be configured to apply heat to the clad-coatedsubstrate in any arrangement, in a particular embodiment the heat sourceis inserted into an interior cavity of the substrate, such as within apipe or tube, having an interior surface coated with cladding material.To facilitate such arrangement, the substrate and/or the heat sourcetranslates relative to the other. In a particular embodiment, thesubstrate is translated, whereby the substrate is directed to receivethe heat source through an end of the substrate during substratetranslation. Translation of the substrate ceases once the heat sourcereaches a desired arrangement relative to the coated interior substratesurface. The substrate may be rotated as well to also facilitate adesired arrangement relative to the heat source. In particularembodiments, the heat source is supported by a cantilevered structureand the substrate by a translation device or conveyor, which maycomprise as a trolley for example.

Once properly arranged, the atmosphere or environment surrounding theheat source and/or the coated substrate may be controlled prior toapplication of heat during any bonding operation. Any known means ofcontrolling or treating the environment may be employed. For example, inparticular embodiments, controlling includes injecting a flow of gasinto the substrate internal cavity. Furthermore, such gas may compriseany desired gas, including an inert gas, such as argon, or any mixtureof gases discharged about the bonding area (i.e., the location whereheat is applied to the coated substrate—which is also referred to as theheat-affected zone). Exemplary methods include forming a vacuum orinjecting a fluid such as any gas, liquid, or reactive fluid about thebonding area (i.e., the location where heat is applied to the coatedsubstrate). It is understood that an area surrounding the bonding areamay be at least partially sealed for improved control, including theability to retain gas injected into the substrate interior cavity. Forexample, where cladding is being applied to the interior surface of apipe, the interior of the pipe may be at least partially sealed andreceive any inert gas, such as argon, to control the atmospheresurrounding the bonding area. Accordingly, in particular embodiments,the step of controlling includes forming at least a partial barrieracross a transverse width of the substrate interior cavity on each sideof the heat source, where the flow of gas is injected between thepartial barriers.

As discussed above, the heat source applies heat to the coated substrateto metallurgically bond the cladding material to the substrate. Inparticular embodiments, cladding material is exposed to high energydensity from an infrared thermal source, such as a high energy densityinfrared (HDIR) plasma arc lamp providing a heat flux (i.e., powerdensity) of 350-5700 W/cm² or more, or a medium density infrared lampproviding a heat flux of 150-350 W/cm², each of which may maintain saidheat flux for a sufficient amount of time to cause the coating materialto flow and to wet the surface of the substrate. In other embodiments,the heat source may comprise any other known heat source known to one ofordinary skill, such as tungsten halogen lamps, induction heat sources,or gas radiant heat sources. In particular methods, the claddingmaterial is exposed to the HDIR plasma arc lamp (or other heat source)at a low power level in order to preheat the material if needed. Thislow power level can be maintained for sufficient time to allow thermalequilibrium to occur within the cladding material. Upon reaching thermalequilibrium, or at any other desired instance, the HDIR plasma arc lamp(or other heat source) is increased to a desired or preselected higherpower level and applied for a desired or preselected duration until adesired bond between the cladding material and the substrate is formed.In particular embodiments, the heat or higher power level remainsgenerally constant over the duration. In other embodiments, the heat orhigher power level is applied in pulses for shorter durations. Forexample, the HDIR plasma arc lamp (or other heat source) is pulsed at apreselected higher level power and for a preselected duration, and thenbrought back down to a preheat power level or lower and held for apreselected time, each of which may be repeated to apply sufficientamounts of energy in short bursts over large areas as dictated by theheat source. Particular parameters of the infrared thermal source and/orthe system may be provided and/or controlled to achieve a desired cladproduct in any desired application. For example, the thermal flux and/orintensity, the size of the heat source, and the transition speed of theheat source or substrate may be controlled to achieve a desired result.It is understood that heating and cladding may be performed using asingle pass or multiple passes, which includes overlapping adjacentpasses (such as overlapping a prior pass with a current pass).Furthermore, employing multiple passes may operate as a substitute forpulsing the heat source. In particular embodiments, when supplyingsufficient quantity of argon within the substrate internal cavity ascontemplated above, the electrical properties are altered such that ashort can occur when energizing the HDIR plasma arc lamp within thesubstrate internal cavity. Accordingly, particular embodiments of suchmethods provide that the heat source is energized outside the interiorcavity, and prior to inserting the heat source within or adjacent to thesubstrate.

In particular embodiments, rapid heating may also be achieved byradiofrequency (RF) induction operating generally between frequencies of20-450 kilohertz (kHz). In other embodiments, other known heatingsources may be employed for rapid heating, such as a microwave heatsource operating generally between 0.3-300 gigahertz (GHz). Further, anycombination of heat sources may be employed together or in sequence toachieve the desired heating. For example, radiofrequency (RF),microwave, and/or infrared (IR) heat sources may be employed to provideRF, microwaves, and/or IR heat in a sequential manner. By specificexample, the RF heat may be used to preheat a substrate and the IR heat(which may be pulsed) to bond the cladding material to the substrate.According to any method of applying heat contemplated herein, rapidheating may be applied in two or more pulses to enable a specifiedthermal profile to be obtained. Further, one or more of the pulses maycomprise a significantly higher energy/heat flux than is provided byother pulses. For example, one or more pulses may be employed to preheatthe substrate or the coating/substrate interface, and a second pulseused to bond the coating to the substrate.

It is understood that the cladding processes generally described abovemay be achieved in a continuous or discontinuous manner. Further, thecladding process may be applied in series with any other substrateoperation, such as substrate forming operations, whereby pipe, sheet,extrusion, or plate is formed according to any known procedure.Furthermore, the cladding composition may be deposited or applied to thesubstrate during or just prior to heating operations. Even further,prior to applying the cladding composition, the interior surface may becleaned by any chemical and/or mechanical process, such as by usingchemical solvents to clean or etching the surface, or by sand blastingthe surface. By further example, the substrate may be quenched orcooled. This may be performed after the substrate is heated and thecladding formed along the substrate. Furthermore, a portion of thesubstrate may be quenched or cooled while portions of the substrate arebeing heated and clad. Even further, a portion of the substrate may bequenched or cooled simultaneously with or prior to the portion of thesubstrate being heated and clad. Quenching or cooling may be achieved byany known means or method, such as by convection (such as by gas orliquid) and/or conduction (such as by contacting the clad substrate witha cool plate).

After forming the clad metal product, the product may be inspected toensure a product of desired quality has been formed. For example, thecladding may be inspected to determine the presence of any cracks,porosity, or other defects. In particular embodiments, the clad metalproduct is subjected to non-destructive testing. Non-destructive testingmethods may include any known technique, such as electromagnetic testing(ET), infrared and thermal testing (IR), radiographic testing (RT), andultrasonic testing (UT). Such testing may be real-time testing, such asreal time radiographic testing (RTR).

Exemplary embodiments of a cladding device for use in performing suchmethods are discussed in further detail below.

With reference to FIGS. 1-2, an apparatus or system 10 for use incladding the interior surfaces of a substrate 80 is shown. Apparatus 10generally includes a heat source-retaining structure 20 (also referredto as “heat source carriage” for simplicity) and a substrate-retainingstructure 60 (also referred to as “substrate carriage” for simplicity),which is also a substrate translation device in the embodiment shown.Heat source carriage 20 includes a heat source 32 for metallurgicallybonding (i.e., fusing) a cladding or coating composition 84 to asubstrate 80 to form a composite body. In the embodiment shown,substrate 80 is a pipe having a desired length, but the apparatusdiscussed hereafter in accordance with various embodiments may be usedwith a tube or any other desired substrate contemplated herein.Accordingly, substrate 80 may comprise any desired substratecontemplated herein, including any tube, beam, extrusion, or channel,including any substrate having an interior surface and/or a transversecross-sectional shape that is closed (such as with a tube or pipe havingan interior cavity) or any transverse cross-sectional shape that ispartially closed (such as with a channel or beam).

Before heat source 32 applies heat to the coated substrate 80, acladding composition 84 is applied to a cladding surface of substrate80. With reference to FIG. 15, in an exemplary embodiment, claddingcomposition 84 is applied to an interior surface 82 of a pipe 80. In theembodiment shown, a portion 84 a of cladding composition 84 has beenbonded to the substrate, while another portion 84 h awaits heating fromthe heat source. The interior surface 82 may be cleaned or otherwisetreated prior to applying the cladding composition. Cladding or coatingcomposition 84 may comprise any desired composition, including thecladding compositions discussed above. Further, coating of the surfacemay occur before the substrate 80 is plated within system 10, or whilewithin system 10, such as when the substrate enters system 10, whilesubstrate is being translated within system 10 as substrate approachesheat source 32.

With specific reference to FIG. 1, heat source carriage 20 includes abase 22 from which a cantilevered structure 30 extends. Base 22 simplyforms any structure capable of supporting cantilevered structure 30.Base 22 may include a control system and/or a power source for operatingapparatus 10, including heat source 32. In particular embodiments,cantilever structure 30 is capable of rotating relative to base 22.Accordingly, a shaft or other like device may extend between base 22 andcantilever structure 30 to facilitate rotation of said cantileverstructure by a motor. As shown, the cantilevered structure 30 and asubstrate translation device 60 are inclined relative a ground plane byangle α, whereby the cantilevered structure extends from base 22 suchthat the heat source 32 is effectively cantilevered from the base, thecantilevered structure extending at an inclination a relative to thebase or the ground plane whereby the free end of the cantileveredstructure is elevated above the opposing end of the cantileveredstructure, which is operably connected to the base. It is understoodthat the inclination may comprise any desired angle α. For example, inparticular embodiments, inclination angle α is approximately 5 degrees,0 to 5 degrees, or 5 to 10 degrees or more. Furthermore, at least aportion of the cantilevered structure and the heat source is arrangedwithin the coated substrate, the coated substrate being arranged at aninclination similar to the inclination of the cantilevered structure. Byproviding such inclination, unwanted gases and smoke may better escapethe substrate interior cavity, and, because more weight is applied tothe inclined substrate translation device, the device is more responsiveand better able to move more fluently with lag due to the tension placedon any chain, cable, or other means used to drive the translationdevice.

With continued reference to FIG. 1, cantilevered structure 30 extends ina lengthwise direction from one end operable attached to a base 22 to afree end, and includes a heat source 32 for applying heat to a substrate80 upon which a cladding composition 84 is applied or coated.Cantilevered structure 30 is a structure formed according to soundengineering principles to support the heat source and all othercomponents attached to the cantilevered structure 30. For example,cantilevered structure 30 may include a plurality of trusses, beams(including I-beams), pipes, tubes, and/or channels arranged along thelength of structure 30. It is understood that structure 30 may also beformed of any suitable material, including steel for example, by anyknown process, such as welding or by use of fasteners, for example. Thecantilevered structure 30 may be pre-stressed, meaning that the beam isformed such that it curves upward from the base 22 to the cantileveredend so that when it is installed onto the base with the heat source andall other components or otherwise becoming loaded, the terminal end ofthe cantilevered structure will be suspended elevationally as desired.

In particular embodiments, apparatus 10 is capable of controlling theatmosphere within or along the substrate during the cladding operation.More specifically, with regard to the embodiment shown, heat sourcecarriage 20 includes means for controlling the atmosphere within thepipe and at least in the vicinity of the heat source 32. In particularembodiments, the means for controlling comprises gas outlets arranged onor between the enclosure members arranged to discharge gas between theheat source and the interior surface of the substrate. Such gas outletsmay be arranged at any location along the length of structure 30. Infurther embodiments, which may or may not include gas outlets, the meansfor controlling includes forming at least a partial barrier across atransverse width of the substrate interior cavity on each side of theheat source, where the flow of gas is injected between the partialbarriers. In particular embodiments, the partial barriers formed onopposing sides of the heat source comprise a pair of enclosures (alsoreferred to as enclosure members) each arranged on opposite sides of theheat source along the length of the cantilevered structure andconfigured to extend at least partially across the transverse width ofthe substrate interior cavity. In more specific embodiments, at leastone of the enclosures including outlets for discharging a flow of gasinto the atmosphere surrounding the heat source and at least apportionof the cladding composition arranged along the interior of the pipe. Forexample, with continued reference to FIGS. 1-3, heat source 32 isarranged between a first enclosure 34 and a second enclosure 36 alongthe length of cantilevered structure 30. First enclosure 34 and secondenclosure 36 generally radiate outwardly (i.e., extend in a directiongenerally perpendicular to the lengthwise direction of structure 30)from the cantilevered structure 30 and extend around said structure 30to generally provide a seal when arranged within pipe 80 for the purposeof isolating the atmosphere within the pipe from the atmosphere outsidethe pipe. However, it is understood that each enclosure 34, 36 may notbe sized identically to the inside dimensions of each pipe 80 withinwhich each is employed. Accordingly, an allowable gap may exist betweenthe interior surface of the pipe 80 (which may have cladding compositionarranged thereon) and the outer extents of the enclosure 34, 36. Thisallows a enclosure 34, 36 to be used with an acceptable range ofdifferently sized pipes, as well as accounting for any variations inpipe manufacturing. If the anticipated gap is too large to adequatelymaintain the desired atmosphere within the pipe, a differently sizedenclosure may be used to achieve the proper sealing capabilities.

It is understood that enclosures 34, 36 may be formed of any suitablestructure, such as a plate, extrusion, or sheet, and any suitablematerial, such as steel, for example, and may be formed by any knownmanufacturing method. Further, second enclosure 36 may include variousapertures through which a pipe, tubing, wired, and/or buses travel tocommunicate power, gases, liquids, and control circuitry, for example,to and from the heat source arranged between enclosures 34, 36. In thepresent embodiment, any input or output of the heat source 32, such aswaste discharge, is routed through apertures within the second enclosure36 (which are exemplarily shown in FIG. 4) and not the first enclosure34 so that all input and output to heat source is routed through oneside of the cantilevered structure, such as through the side or endopposite the free end of the cantilevered structure. More generally, theinput and output of the heat source 32 is routed away from the free (orterminal) end of structure 30 to allow any pipe to enter and exitstructure 30 without interference.

In the exemplary embodiment shown in FIG. 1, structure 30 has a lengththat is at least as long as a substrate 80 (such as the pipe shown, forexample) to be clad by system 10. In particular embodiments, the lengthbetween enclosures 34, 36, is at least equal to the length of thesubstrate. When structure 30 is at least as long pipe 80, the entirelength of pipe 80 may be exposed to heat source 32 and bond claddingcomposition 84 along such length. This allows a pipe 80 that isinstalled heat source 32 to travel from a first end of the pipe to asecond end of the pipe for the purpose of coating a full length of thepipe. In the exemplary embodiment, first and second enclosures 34, 36are spaced from heat source to protect the enclosures from the heatdischarged by the heat source. Therefore, when the pipe is installedalong the cantilevered structure 30 and a first end of the pipe isarranged adjacent the heat source 32, the first enclosure 34 is spacedfrom the first pipe end. Accordingly, to allow first enclosure 34 tosufficiently separate the exterior environment from the pipe interiorwhile the heat source 32, a substrate extension 80A is attached to thefirst end of pipe 80. To achieve its purpose, the extension 80A has alength at least as long as the distance between the heat source 32 andthe first enclosure 34, which is referred to as length L_(80A). For thesame purpose, a second extension (not shown) may be arranged oppositethe first extension along the second end of pipe 80, so to extendbetween the second pipe end and the second enclosure 36 for the purposeof separating the exterior environment from the pipe interior when theheat source 32 is arranged at the second pipe end. Accordingly, thesecond extension has a length at least as long as the distance betweenthe heat source 32 and the second enclosure 36, which is referred to aslength L_(80B). To reduce the length of each extension, the enclosuresmay be arranged closer to the heat source. In the alternative, a longerlength pipe may be employed, where portions at the first and second endsare not clad and cut from the clad portions to provide a final cladpipe. Each extension may be releasably secured to the pipe, such as byway of fasteners. In other variations, the extension is welded to thepipe and later cut after the pipe has been clad.

Heat source 32 may comprise any desired heat source, such as a heatlamp, for example. In the embodiment shown in FIGS. 1 and 10, heatsource 32 is an infrared (IR) plasma arc lamp, which may be a mediumdensity infrared lamp or a high density infrared (HDIR) lamp asdiscussed previously. IR plasma arc lamp 32 includes a reflector 32 aand an anode and cathode (not shown) arranged on opposing sides of thereflector 32 a. In the embodiment shown, heat is discharged from heatdischarge opening 33 arranged along a bottom side of reflector 32 atoward an interior bottom surface 82 of the pipe 80. As discussedpreviously, however, heat source 32 may comprise any other known heatsource or combination of heat sources discussed above capable ofachieving the cladding operations discussed herein, and, as well mayinclude multiple discharge openings. The heating process utilizing theHDIR plasma arc lamp is capable of quickly delivering large amounts ofcontrolled heat over large surface areas with little or no detrimentalinfluence on the substrate (i.e., the base material). Pulses of infraredenergy from the HDIR arc lamp can be as short in duration and/orperiodicity as the physical limitations of the device that produces theplasma arc, in a manner that allows precise control various processparameters, such as work-piece surface temperature. The heating processcan be carried out in a controlled environment between enclosures 34,36. The controlled environment may comprise a vacuum or contain aparticular air, liquid, inert fluid, or reactive fluid, for example, orany other type of environment needed for processing. A means forquenching or cooling the pipe or substrate after heating during thebonding process is contemplated and may be arranged along an outersurface of the pipe, where such means may be mounted to either carriage20, 60 or another structure.

Apparatus 10 may include a means for controlling the environment alongthe substrate for application heat and performance of claddingoperations. For example, with reference to FIGS. 1, 3-9, in particularembodiments of the invention, means for controlling the environmentcomprises a means for discharging gas, which may comprise any gasdischarging device such as gas discharging ring 38, for example, toassist in controlling the environment within pipe 80. Ring 38 includesat least one gas inlet 44 and a plurality of gas outlets 48 for thedistribution of gas into pipe 80. In the embodiment shown, outlets 48comprise cylindrical openings. In other variations, outlets 48 maycomprise any one or more other sized and shaped opening, including asone or more slits. Gas may be injected into pipe 80 for the purpose ofcontrolling the inside atmosphere and operating as a shielding gasduring the fusion process of the cladding material. For example, argonmay be discharged from ring 38 as a shielding gas. Gas inlets 44, shownadjacent apertures 42 along tabs 40 for receiving mounting fasteners,are in fluid communication with a gas distribution channel 46 extendingannularly around ring 38. In embodiments shown, the gas discharging ring38 is arranged in conjunction with second enclosure 36, which is used toclose channel 46 for the purpose of forming a gas distribution passage49 for directing the gas from the inlet 44 to each outlet 48. It isunderstood that any other ring design and arrangement may be employedwhich provides at least one gas inlet, a plurality of gas outlets, andat least one gas distribution passage in fluid communication with bothan inlet and an outlet—whether or not such ring is arranged inconjunction with a enclosure 34, 36 or any other component.

Gas outlets 48 are shown arranged generally near the outer radialextents or sides of the ring 38. Gas outlets may be arranged to providelaminar or non-turbulent flow. The gas is discharged in this arrangementto account for any gap between the enclosure/ring and the pipe. Morespecifically, a first arrangement of outlets 48 are shown arranged alonga first outer surface 50 arranged along the outermost extend or side ofring 38, the surface generally extending in an axial direction of thering. The outlets 48 of first surface 50 primarily direct gas outwardlyin a generally radial direction and into the vicinity of any gapexisting between any pipe 80 and the enclosure 36 and/or ring 38 for thepurpose of preventing or reducing the influx of any external atmosphere.A second surface 52 arranged more inward from the first surface 50directs flow in a more inward direction of pipe 80 (i.e., toward theheat source 32) for the purpose of filling the interior of the pipe withthe discharged gas at least partially or even fully. In the embodimentshown, the second surface 52 is an inclined surface, whereby the surfaceextends radially inwardly from an outer location of the ring to a morecentral location of the ring. It is understood that any desired ringdesign may be employed consistent with this invention, where such ringmay include any desired arrangement of outlets and surfaces. Ring 38 maybe formed of any desired material, such as aluminum or steel, and may beformed by any known process, such as casting or machining. In theembodiment shown, the ring 38 is formed of multiple sections and employsapertures for receiving guide pins to assist in the alignment ofadjacent sections during ring assembly.

In an effort to accommodate differently sized substrates, a differentlysized ring 38 may be employed. In further embodiments, whenaccommodating a substrate having a transversely larger interior cavity(that is, a taller and/or wider internal cavity), one or more additionalgas outlets may be arranged radially outward the ring to accommodate thelarger interior cavity. Similarly, in any such instance, differentlysized transverse barriers, such as enclosures 36, may be employed whenaccommodating differently sized substrates. For example, whenaccommodating larger interior cavities, a larger barrier may be providedby substituting a larger bather for the smaller barrier, or one or moreextensions may be added to the smaller barrier. For example, withreference to FIGS. 6-9, a secondary member 54 (also referred to as anextension) is shown attached to a ring 38, where the member is annularlyshaped and includes a plurality of gas outlets 55 spaced radiallyoutward from the ring. The gas outlets 55 extend from a channel 57formed into a back side of the secondary member between gas inlets 56.The channel is enclosed by cover 58, which includes apertures 59 forreceiving a gas input line, the apertures being aligned with inlets 56along member 54. Secondary member also operates to form a largerbarrier, and may be provided whether or not secondary member includesgas outlets 55. With reference to FIGS. 7 and 8, gas supply lines 39 areshown operably attached to ring 38 and secondary member 54, and inparticular gas inlets 44 and 56, respectively.

As discussed above, a means for protecting the heat source frompotential damage that may result during a bonding operation, such as dueto reflective heat or due to the present of certain gases, contaminants,splatter, or other projectiles, may be provided. Any means forprotecting the heat source may be employed, including a means forshielding the heat source that directs a flow of air or gas across theheat source to create a barrier between the heat source and a particularenvironment. With reference again to FIGS. 1, 10, and 12, the particularembodiment shown provides a means for shielding the heat sourcecomprising a gas shielding device 90, which is arranged adjacent theheat discharge opening 33 of heat lamp 32. Shielding device 90 receivespressurized gas that is then distributed outwardly through outlet 96 andthereby discharges a flow of gas across the heat discharge opening 33 ofthe lamp to protect the interior of the lamp by deterring or preventingentry through the outlet 96. The flow of gas may be discharged in anydirection across the discharge opening. In the embodiment shown, the gasflow is directed in a lengthwise direction of discharge opening 33 alongopening length L₃₃. By further example, shielding device 90 may bedirected transversely across discharge opening 33 in a widthwisedirection of the opening along opening width W₃₃. In particularembodiments, the flow of gas is controlled to provide a laminar flow ofgas. This flow of gas provides a fluid barrier (of moving gas) betweenthe environment and the inside of the lamp accessed through thedischarge opening. The flow of gas is intended to protect the heat lampor heat source from any material, fluid, or other gases resulting fromthe bonding process (as discussed in further detail above). The gasdischarged from shielding device 90 may comprise any desired gas,including any inert gas such as argon.

The means for shielding the heat lamp or heat source may comprise anydesired method, system, or apparatus. With specific reference to FIGS.11-14, the shielding device 90 includes gas inlet 92 and gasdistributing cavities 94 extending between inlet 92 and outlet 96.Cavities 94 expand in width as each extend in length or depth outwardlytoward outlet 96 to provide a maximum width W₉₄. In the embodimentshown, expansion in cavity width along sidewalls 94 a occurs linearly,but in other embodiments, such expansion may occur non-linearly. Forexample, in lieu of extending linearly, the cavity sidewalls 94 a extendalong a non-linear path, including any curvilinear, concave, or convexpath. Further, outlet 96 has a width W₉₆ sufficient to create a gas flowof sufficient width as desired to span heat source 32. While the widthof outlet is shown to be approximately equal to the final expanded widthof the combined cavities 94, the width of outlet 96 may be wider ornarrow than the width of cavities 94 (that is, the combination ofcavities 94), or of any single cavity 94 when only once cavity 94 isprovided. The height H₉₆ of outlet 96 is sufficiently sized to produce agas flow of desired quality and character, which may, for example,provide a laminar gas flow. Outlet 96 has a height that is shorter thanthe height of cavities 94, although, in other embodiments, the height ofthe outlet maybe equal to, or even larger than the height of cavities94. It is understood, however, that one or more shielding devices may beemployed and arranged in any relation to discharge opening 33. Forexample, the device of FIG. 10 is arranged to direct flow in a widthwisedirection of discharge opening 33 spanning the opening width W₃₃, suchthat the width of the air flow is directed across the opening lengthL₃₃. Accordingly, it is understood that the width W₉₆ of outlet 96 mayspan any desired distance. For example, outlet width W₉₆ may beapproximately equal to or greater than a width W₃₃ of heat sourcedischarge opening 33. Furthermore, when more than one shielding device90 is employed to create the width of a flow barrier, the width of eachshielding device may be selected such that the sum of all the widths W₉₆of the plurality of shielding devices is approximately equal to orgreater than the flow barrier width—which may be less than, greaterthan, or equal to the width W₃₃ or length L₃₃ of the heat sourcedischarge opening 33. For example, in particular embodiments, the widthW₉₆ of outlet 96 is approximately 3 inches, which is approximately equalto the heat source discharge opening width W₃₃, which is equal to 3.285inches. In such instances, for example, the height H₉₆ of the outlet isequal to 0.002 inches to 0.020 inches. In it understood that outletheight H₉₆ may comprise any distance, and, may be selected (increased ordecreased) as desired to adjust the flow rate and/or the thickness ofthe flow barrier. While any desired flow rate may be employed, exemplaryflow rates discharged from shielding device 90 range from 10 to 100standard cubic feet per hour (SCFH). In other examples, the shieldingdevice may comprise an air knife or a blower.

With reference to FIG. 12, a intermediate cavity 95 extends betweencavities 94 and outlet 96. In particular, intermediate cavity 95 isarranged adjacent outlet 96 and recessed or offset below cavities 94.Cavity 95, as shown, has a width W₉₅ equal to the final width W₉₄ ofcavities 94, although it may be larger or smaller as desired. Thisarrangement may be employed to control the flow of gas from outlet 96,although it is understood that control of the flow may be achieved whenintermediate cavity 95 extends elevationally from a location within theheight of any cavity 94 or above any cavity 94. Likewise, if outlet 96has a height equal to cavities 94, the intermediate cavity 95 is eithernot present or forms a portion of the cavities, or an extension thereof.Because the shielding device 90 may be closely located to the heatsource, cooling conduits 98 having ports 99 are provided for coolant totravel during bonding operations to protect shielding device fromexcessive heating. In the embodiment shown, device 90 is assembled frommultiple portions, namely, a first portion 90A and a second portion 90B.

As suggested above, a means for translating or moving the substrate maybe provided. Such means may comprise any method, system, or translationdevice capable of translating the substrate relative the heat source.Such means may comprise, for example, a translation device comprising aconveyor belt, a series of rollers, or any other known means fortransporting or conveying an object. By further example, with specificreference to FIGS. 1-3, translation device comprises a substratecarriage 60 including a substrate retention subsystem 62 for receivingand retaining substrate 80. Retention subsystem 62 may comprise anydesired form capable of retaining any desired substrate 80 withincarriage 60. In the embodiment shown, retention subsystem 62 includes aplurality of wheels 64 (or rollers), and in particular two (2) pairs ofwheels 64, arranged to receive and retain a pipe 80 in a cradle-likearrangement, where a first pair of wheels are spaced laterally from asecond pair of wheel to create a substrate receiving area 66. In theembodiment shown, each pair of wheels share an axle 68 and are mountedto a first base structure 70. It is understood that any wheel, and inparticular at least one of the wheels 64 of any pair may be driven torotate pipe 80 as desired. Any such wheel may be driven by any knownmeans, such as a motor.

In particular embodiments, retention subsystem 62 may be raised orlowered as desired to adjust the spacing and alignment of the substrate80 relative to the heat source carriage 20 and heat source 32, which mayfacilitate proper alignment of pipe 80 along cantilevered structure 30and provide a desired spacing between the heat source 32 and thesubstrate 80 for desired bonding operations. Accordingly, an elevational(or vertical) adjustment means 72 for raising or lowering retentionsubsystem 62 may be employed, which may comprises any known raising orlowering means known to one of ordinary skill in the art. For example,elevational adjustment means 72 may comprise hydraulic or pneumaticcylinders, or screw devices used to adjust the vertical arrangement ofretention subsystem 62 and of substrate 80. It is understood that atleast a portion of heat source carriage 20 includes means for adjustingits vertical arrangement relative to substrate 80.

Carriage 60 may include a translation means 74 to facilitate translationof substrate 80 relative to heat source carriage 20. Translation means74 are shown to comprise wheels operably attached to a second base 76 ofcarriage 60. At least one of the wheels may be driven in particularembodiments. In other embodiments, however, translation means 74 maycomprise any other means of translating carriage 60 known to one ofordinary skill in the art. It is understood that substrate carriage 60may remain fixed while heat source carriage 20 is translatable tofacilitate relative translation between substrate 80 and heat source 32.

To assist in maintaining proper pipe alignment relative to cantileveredstructure 30, a means for aligning the substrate relative the heatsource-retaining structure 20 may be employed. Such means for aligningmay also operate to further support the cantilevered structure 30. It isunderstood that the means for aligning may comprise any method, system,or apparatus for aligning the substrate relative the heat-sourceretaining structure, including the heat source retained therein. Forexample, such means for aligning may comprise an air bearing or anmagnetic levitation device. By further example, with reference to FIGS.16-19, means for aligning may comprise an alignment means comprising oneor more extensions 100 extending radially from structure 30 to engagethe inside surface 82 of pipe 80. By utilizing one or more extensions100, the spacing between pipe 80 and the heat source 32 is bettercontrolled, such as when the pipe dimensions vary due to manufacturingvariations. In the embodiment shown, a first extension 104 extendsdownwardly a desired distance from a central member 102, the distanceselected to space an inside surface from the heat source by a distance D(shown in FIG. 15). Distance D may be adjusted based upon a thickness ofcladding composition 84 arranged along surface 82. Second extension 106and third extension 108 extend upwardly from central member 102 biasedby an angle A in opposite directions from a vertical plane P extendinglongitudinally along the length of structure 30. While extensions 104,106, 108 are arranged symmetrically about vertical plane P, suchextensions may be arranged asymmetrically about vertical plane P oraround the origin from which angle A extends. For example, the angle Amay be different between one or more extensions 104, 106, 108. In thepresent embodiment, central member 102 extends axially along structure30 from first enclosure 34. First enclosure 34 may include an aperture35 for receiving central member 102 for operable attachment of saidcentral member. Central member 102 may or may extend along a centralaxis of structure 30. Likewise, aperture 35 may or may not be arrangedalong a central axis of first enclosure 34 and/or a central axis ofstructure 30. It is understood that one or more extensions 104, 106, 108extending in any desired direction may be employed in other variations.Further, extensions 104,106,108 may not extend from central member 102and may instead extend from any other portion of structure 30, such asbetween first and second enclosures 34, 36, for example.

With continued reference to FIGS. 16-19, each of the extensions 104,106, 108 include a bearing means 110 arranged at the terminal endsthereof for engaging the interior pipe surface 82. In the exemplaryembodiment shown, the bearing means is a rotatable ball bearingmaintained within a bearing housing 112. In the alternative, bearingmeans may comprise any known means for facilitating a translationdifferential between the pipe 80 and structure 30 while thecorresponding extension engages the pipe. In the present embodiment, thesecond and third extensions 106, 108 are radially displaceable toaccount for variations in the pipe dimensions. Accordingly, a forced orbiased displacement member 114 is arranged along second and thirdextensions to facilitate displacement of each bearing means 110.Displacement member 114 may remain free to radially displace bearingmeans as necessary to account for any dimensional variations in pipe 80.In the embodiment shown, displacement member 114 comprises a compressionspring, which is compressed to forcefully bias bearing means 110radially outward against interior pipe surface 82. To transmit the loadof spring 114, a piston 116 generally extends between spring 114 andbearing housing 112. Each spring 114 is retained within a cavity 118surrounded by a sleeve 120 or outer wall 120. Alternatively, in lieu ofa compression spring, any other spring or means for forcefully biasingbearing means against the pipe known to one of ordinary skill may beemployed. To maintain a constant, desired distance D between heat source32 and pipe surface 82, first extension 104 remains rigid during thetranslation of pipe 80 along cantilevered structure 30. However, each ofthe extensions 104, 106, 108 may have adjustable lengths to accommodatedifferent sized pipe, where such adjustments are made prior tosubstantial translation of pipe 80 along structure 30. In otherembodiments, in lieu of extensions 104, 106, 108, other alignment meanscapable of maintaining the interior surface 82 of the pipe a distance Dfrom heat source 32 may be employed. For example, air bearings, magneticlevitation (which is also referred to as “maglev”), or magneticsuspension principles may be employed to control the alignment of pipe80 relative to heat source 32.

While this invention has been described with reference to particularembodiments thereof, it shall be understood that such description is byway of illustration and not by way of limitation. Accordingly, the scopeand content of the invention are to be defined only by the terms of theappended claims. The use of words and phrases herein with reference tospecific embodiments, as will be understood by those skilled in the art,does not limit the meanings of such words and phrases to those specificembodiments. Words and phrases herein have their ordinary meanings inthe art, unless a specific definition is set forth at length herein.

1-18. (canceled) 19: An apparatus for metallurgically bonding claddingmaterial onto a metal substrate, the apparatus comprising: a heat sourcehousing, the housing comprising a cantilevered structure, thecantilevered structure including a heat source arranged along a lengthof the cantilevered structure and comprising an infrared, microwave, orradio frequency heat source; and, a translation device adapted toreceive a metal substrate comprising a pipe or a tube, the translationdevice being translatable relative to the heat source and configured torotate the substrate relative the heat source. 20: The apparatus ofclaim 19 further comprising: a pair of enclosure members each arrangedon opposite sides of the heat source along the length of thecantilevered structure and configured to extend at least partiallyacross a cross-section of the substrate. 21: The apparatus of claim 20further comprising: gas outlets arranged on or between the enclosuremembers arranged to discharge gas between the heat source and theinterior surface of the substrate. 22: The apparatus of claim 19,wherein the heat source is a high-density infrared plasma arc lamp. 23:The apparatus of claim 19 further comprising: a gas flow source arrangedadjacent to the heat lamp, the gas source having an outlet directing agas flow from the outlet and across a heat-discharging portion of thelamp between the heat-discharging portion and the interior surface ofthe substrate. 24: The apparatus of claim 19, where the one of theenclosure members including outlets for discharging a desired gasincludes a ring, the ring including the outlets for discharging thedesired gas, the outlets being spaced apart in an annular arrangementabout the ring. 25: The apparatus of claim 19, where the cantileveredstructure extends longitudinally at an inclination to a ground plane,whereby the free end of the cantilevered structure is elevated above theopposing end of the structure. 26: The apparatus of claim 14, whereinone of the conveyor and the cantilevered structure are configured toadjust a relative distance between each other for the purpose ofadjusting the distance between the substrate retained along the conveyorand the heat source of the cantilevered structure. 27: The apparatus ofclaim 14, wherein the cantilevered structure is rotatable relative to abase to which the cantilevered structure is operably attached. 28: Theapparatus of claim 14, wherein one or more extensions protrude radiallyfrom the cantilevered structure, each of the one or more extensionshaving a bearing means arranged at a free, terminal end of the extensionfor engaging an interior surface of the substrate.